An attempt to educate students about the risk factors that may eventually result in diseases. It is now unacceptable to wait until preventable diseases occur and then offer remedies. Future physicians will not only diagnose and treat diseases such as coronary artery, bypass graft, or percutaneous transluminal coronary angioplasty, but they will help patients prevent the abnormalities responsible for the diseases. Recognizing risk factors leads to specific therapy for high risk patients with hypertension, abnormal lipids, obesity, diabetes, emphysema, etc. Certain diseases cluster, thus sharing a common pathogenetic mechanism, or common underlying risk factor. The insulin resistance syndrome is characterized by diabetes, obesity, hypertension, dyslipidemia (high cholesterol), atherosclerosis (clogging of medium and large arteries by plaque-like deposits), and hyperandrogenism (excessive secretion of masculating substances). Emphasis will be placed on these factors, some of the most prevalent in western societies. Volunteer students will be admitted to the GCRC for one night during the first semester of medical school. After admission, students will be interviewed by a nutritionist to obtain a typical 24 hour intake, food frequency, and preliminary information as to life style behaviors. Skinfold measurement to determine body fat, Body Mass Index, and Waist Hip Ratio will be taken during the interview. A life style questionnaire will be filled out by the student. After an evening meal, the student will fast until 8:00a.m. the next day. The student will collect a timed urine for nitrogen analysis. Before arising and while supine, the student will undergo indirect calorimetry to determine resting energy expenditure and substrate oxidation. This is achieved by placing a plastic, ventilated canopy over the head for approximately 20 minutes while oxygen consumption and carbondioxide production are measured. Blood samples of no more than 30cc. will be obtained for the measurement of glucose, insulin, dehydroepiandrosterone (DHEA), fasting lipid profile, and blood chemistries. Bioelectrical impedence will also be performed. The student will then receive breakfast.